Process of treating coal



June 2, 1931.

c. P. ANDERSON 1,807,817

PROCESS TREATING COAL Filed Jan. 29, 1930 Inventor Patented June 2, 1931 CHARLES P. ANDERSON, OFF SGARBRO, WEST VIRGINIA -ZPROCESS or TREATING GOAL Application filed January 29, 1930. Serial No. 124,314.

This invention relates to a process of treating coal and is particularly adapted to treating bituminous and anthracite coals.

An object of the invention is to provide 6 a process that in a continuous operation will separate the impurities from the run of mine coal and all sizes of screened coal and at the same time provide for rendering the coal dustless after the treatment.

Further objects of the invention are to provide a process, the outcome of which causes more complete combustion of the coal and reduces the amount of smoke.

With the foregoing and other objects in View, the invention consists of a novel treating operation that-will be more particularly described and illustrated in the accompanying specification, wherein is disclosed an em bodiment of the invention, but it is to be understood that changes, variations and modifications may be resorted to without departing from the -spirit of the claims hereto appended.

The figure in the drawing, represents a diagrammatic treating operation in accordance with the resent invention.

It has een proposed to separate impurities from coal by the use of calcium or zinc chloride solution of a specific gravity to ef- 3tl coal-in an aqueous solution formed of salts or mixtures of salts ofcertain metals, such as those of certain alkaline earthfmetals, the specific gravity of which has beenbuilt up to cause the coal to float on the surface and the impurities to settle to the bottom of the container used in the treatment.

feet the flotation of the coal but as far as the" In a continuous operation the coal of my invention, is then taken from the solution Without any washingor other treatment and stored in. bins for future use or loading in railroad cars or passing over screens to be loaded in trucks or railroad cars, and with this practice in mind it will be found that the solution, by capillary attraction, will adhere to or penetrate beneath the surface of the coal and this adhesion and penetration will not only render the coal dustless but will create a more perfect combustion, thereby retarding the smoke and at the same time increasing the B. t. u. value of the coal. The average practically available heat content of coals coming from a particular field in West Virginia, where experiments have been made, average about 14,800 B. t. u. per ton, whereas an average value, after treatment in accordance with the present invention will result in a coal having approximate- 1y 15,250 B. t. u.

Moreover, an analysis of the coal after treatment, shows a considerable reduction in ash from which it is to be presumed that there is a more perfect combustion and a noticeable decrease in the amount of smoke.

In explaining the process of the treating of the coal and referring to the drawings in detail, 1 represents a chute from which screened run of mine coal is to be treated. By this latter term is meant coal as it comes from the mine containing clay, slateydirt, and other refuse; Coal passes. from the chute into a reservoir 2 that may be supported on any elevated superstructure 3.

The average specific gravity of coal ofbituminous character ranges from 1.28 to 1.46 and coal of anthracite character ranges from 1.40 to 1.65 and therefore the aqueous solution 4 in the tank is built up so that the specific gravity willfcause the pure coal indicated at 5 to float along the surfaee'of the solution.

The refuse, slate or other impurities being of a heavier specific'gravity and indicatedat 6, will precipitate or sink to the bottom of the reservoir 2. A frame 7 may be suitably supportedasat 8 on the reservoir 2 about which is movably trained an endless conveyor 9 having 'foraminous buckets 10 connected therewith. This conveyor may bearr'anged'in any suitable manner with respect to the reservoir, so.

- as to engage the floating coal 5 and carry the same out of the reservoir.

The coal passes then from the endless conveyor 9 onto another endless conveyor 11 which is associated in proximity to the end of the conveyor 9, whereupon the coal from this latter conveyor 11 will fall in the storage pile 12. y I

The apparatus for carrying outthe invention may be altered as the circumstances require having in mind the most efficient operation for a continuous process. It will be seen from the foregoing description, that the treatment of the coal is continuous and requires the minimum of attentionduring its operation.

. It is preferred to have the lower end of chute 1 below the level of the treating liquid 4 so as to insure complete immersion of the coal in the liquid. Furthermore, it will be noticed that it is preferred to have the lower end of the inlet conveyor 9- spaced from the chute so as to provide suitable spacetherebetween for the coal to float on the surfaceland allow the maximum time for capillary attraction of the salt solution beneath the surface of the coal.

In forming the solution for treating in reservoir 2, an aqueous solution of the salts of certain metals such as magnesium, calcium or other chlorides,'for, example. zinc chloride, is built up to the specific gravity'required in a separate reservoir from the treating reservoir 2 and conveyed into reservoir 2 in any suitable manner. y

In this way, a constant specific gravity of the treating solution is obtained. Obviously, the present invention does-not contemplate any further treatment of the coal after immersion in the metal salttreating solution. thereby eliminating expensive washings that are frequently used on the market today, and

moreover it will be noted that in making an, application of the salt to the coal, use ofthe salt solution, p'prmits the separation of the impurities from t-he coal. which entirely elimi nates expensive separations, heretofore proposed before applying superficial coatings to prevent dust.

It therefore follows that the present inven tion contemplates a continuous operation for separating impurities from coal and rendering the coaldustless, and dustproof, promote ing better combustion with a corresponding reduction in smoke and slightly increasing the B. t. u. value of the coal.

It is to be understood by describing in detail herein any particular form, arrangement, or sequence of operation, it is not intended to limit the invention beyond the terms of the several claims, or the requirements of the prior art.

Having thus described my invention, what I claim as new is 2-- l 1. A method of treatin coal comprising immersing screened run 0 mine-coal in an aqueous solution containing a saltof an alkali metal of a specific gravity to cause the pure coal to float, and permit the heavier impurities to sink, permitting the floating coal to remain in the solution until it has mechanically entrained the maximum amount of the solution and thereafter continuously conveying the coal from the receptacle and caus ng .the coal to permanently retain all of the adsorbed salt. 7

2. A method of treating coal comprising immersing screened run of mine coal in an aqueous solution containing a mixture of a metal salt of a specific gravit to cause the pure coal to float, and permit tlie heavier impurities to sink, permitting the floating coal to remain in the solution until it has mechanically entrained the maximum amount of the solution and thereafter conveying the coal from the receptacle to a place of storage or deposit of the finished product, and causing the coal permanently to retain all of the salt entra ned thereby in said-receptacle.

3. method of treating coal comprising thesingle step of separating impurities from the coal in the presence of a solution of salt ofan alkaline earth metal, and-removing the separated coal as a finished product perma-v nently retaining the adsorbed salt solution.

4; A method 'of treating coal comprising the single step of separating impurities from coal in the presence of a mixture of salt of an alkaline earth metal, and removing the separated coal as a finished product permanently retaining all of the entrained salt mixture.

In testimony whereof I afiix my signature.

CHARLES P. ANDERSON. 

